You may have noticed that there are two words used to talk about springtime in German: das Frühjahr and der Frühling. Sometimes these two words are used interchangeably, like "fall" and "autumn."

However, if we look at the Duden definition of each word, we see that der Frühling is specified as a season in which mild temperatures prevail and plants begin to grow, whereas das Frühjahr is more vaguely defined as the period of time between the end of winter and the end of spring. This may seem like a subtle difference, but means that we will be more likely to hear das Frühjahr used in contexts where we are more generally talking about the transitional months in the early part of the calendar year.

Wir sehen uns im Frühjahr zweitausendneun im Kino. We'll see one another in the spring of two thousand nine at the movies. Caption 29, Filmtrailer: Hexe Lilli

Im Frühjahr zweitausendundelf sollen die ersten Fohlen geboren werden. The first foals are to be born in the spring of two thousand and eleven. Caption 44, Für Tierfreunde: Przewalski-Wildpferde

Unlike das Frühjahr, der Frühling clearly indicates the season (March through May in the Northern Hemisphere), along with its positive connotations of warm weather. If spring is named among other seasons, it will much more likely be referred to as der Frühling, and not das Frühjahr.